Form-lifter



L. M. couvzm;

FORM LIFTER. APPLICATION FILED SEPT. 11, 1920- Patented Nov. 15, 1921.

3 SHEETSSHEET 1.

qlllllll Iill'u NW }I llll Ill wmm -n WIIIIIIII w T/vssEs INVENTOI? L..M Corn/6 ATTORNEYS L. M. CONVERT. FoRM LlFTER.

APPLICATION FILED SEPT. 11', 1920.

Patented Nov. 15, 1921.

.3 SHEETSSHEET 2.

lllllllllllll fl lllll .1. y y 75.25. H N I m fill FZQCM "A 770mm;

Nl'l'E STATES LIN US M. CONVERT, 0F PEORIA, ILLINOIS.

FORM-LIFTER.

Specification of Letters Patent.

Patented Nov. 15, 1921.

Application filed September 11, 1920. Serial No. 409,729.

To all whom it may concern:

forms, used in building construction, wherein the said lifter is adaptedto be connected to the form, and has means for engaglng a supporting rodor pipe so arranged that the lifter carrying the form may be moved upthe pipe, and will hold the form 1n adjusted position.

In the drawings:

Figure 1 is a front View of the lmproved lifter, a

Fig. 2 is a top plan view,

Fig. 3 is a section on the line 3 --3 of Fi 1 *igi is a verticalsection,

Fig. 5 is a side view,

Fig. 6 is a section through one pair of T1 m aws o T i s a perspectiveview of the lower section of the lifter, v

Fig. 8 isa plan view of a pa r of aws,

Fig. 9 is a view of one of thGJLWS looking from the inner side. i i

In the present embodiment ofthe invention the improved lifter consistsof means for engaging the form 1, and comprises a section 2 which isadaptedto be arranged on the upper side of the form,and a section 3which is adapted to be arranged on the underside of the form, the saidsections rigidly secured together by means of bolts and nuts 4, thebolts passlng through reg1stering openings in the sections and in theform.

Each of the sections 2 and 3 is in the form of a cylindrical body havingan enlarged base which seats against the form, and the upper section 2'carries pans of oppositely extending ears 5, the members of the pairsbeing parallel and extendlng 1n the'opposite direction to the members ofthe other pair. 'A palr'of levers 6 and 7 respectively is pivoted toeach pair of cars,

by means of pivotpins8, and referring to Fig. 2 it will be seen thatthose ears to which the levers 7 are pivoted are spaced farther apartthan those ears to which the levers 6 are pivoted, the arrangement beingsuch that the levers Twill lie outside of the levers 6. The free ends ofeach pair of levers are connected by a pivot pin 9 similar to the pins 8before mentioned.

A gripping jaw 10 is supported by each pin 9, and each jaw 10 is shapedon its inner face to fitabout a rodor pipe 11, the rod orpipe passingthrough the sections 2 and 3 and through the form.,

The jaws 10 and the connected mechanism constitutes one gripping device,two of the said devices being-provided, and the other is supportedfromthe section 3. The said other device comprises a frame 12 which isprovided at each end with alined bearings 13 and 14., through which thepipe or rod 11 slides. This frame is supported from the section 3. bymeans of links 15. The

upper ends of the links are received in slots 16 extendinglongitudinally of the section 3, and are engaged by pivot pins 17, topivotally connect the links to the section. The lower ends of the links15 are pivoted to the arms of a yoke shaped lever 28. The arms ofthislever are received in slots 18 in the upper end of the frame 12 and areengaged by pivot pins 19 to pivotally connect the lever to the frame.The frame carries at its lower end oppositely extending pairs of ears20, arranged in the same mannor as the ears 5,, and to each pair of earsthere is pivoted a pair of levers 21 and 22 respectively, correspondingto the levers 6 and 7 of Fig. 2, the levers 22 fitting outside of thelevers 21 in the same manner as the levers 7 fit outside of the levers6. The levers are pivoted to the ears by pivot pins 23, and a grippingjaw 24 is supported between the free ends of each pair of levers, on apin 25. Cotter pins are arranged at the ends of the pins 23 and 25 tohold them in proper position. The jaws 10 are pressed upward away fromthe section 2 by means of a coilspring 26 which is arranged between thejaw and the section 2, and a similar spring 27 is arranged between thejaws 24 and the bearing 14, for a similar purpose. These springs 26 and27 act to tighten the aws, since it is obvious that when the free endsof the levers 6-7 or 2l22 are swung upward the jaws will be tightened onthe rod or pipe, that is they will be moved toward each other.

The "lever 28 extends laterally from the pipe or rod 11, and it will beobvious that when the free end of the lever is swung upwardly the lowerportion of the lifter will be lifted, that is it will be moved closer tothe upper portion while when the outer end of the lever'is moveddownwardly the portions will be moved away from each other.

Referring to Fig. 9 it will be seen that the gripping jaws arecorrugated on their inner faces, the said jaws being concaved to fit thepipe 11, and the concave surfaces have the corrugations. Thesecorrugations face upwardly and it will be evident that when either thesection 2 or the frame 12 is moved upwardly, the engagement of theinclined faces of the corrugations with the pipe or rod 11, tendsto movethe said jaws downwardly against the tension of the spring 26 or 27 asthe case may be, that is to loosen the jaws, while the downward movementof the said jaws with respect to the rod or pipe tends to tighten thejaws.

The operation is as follows: When it is desired to lift the form, thehandle or lever 28 is swung downwardly at its outer end. This movementof the lever tends to tighten the jaws 24E,clamping them more firmly onthe pipe 11, while at the same time the movement lifts the upper portionof the lifter, namely the sections 23. After the lever has beenswungdown at its outer end to the limit of its movement, the outer end isswung upward. This movement of the lever loosens the lower grippingmechanism, the weight of the form holding the upper mechanism ingripping condition. The weight of the form during the lifting of thesame is always supported by one gripping mecha nism while the other ismoving with respect to the form.

I claim:' 1. In a form litter, the combination wit the form and asupporting pipe for the form, of a lifter comprising a section adaptedto be rigidly connected with the form above and below the same andhaving means above the form for engaging the pipe and controlled torelease position by the lifting of the form with respect to thesupporting pipe, and a section supported below the form by the firstnamed section and having means for engaging the pipe controlled torelease position by the lifting of the said section with respect to thesupporting pipe, and means in connection with the last named section andwith the supporting means for lengthening and shortening the connectionbetween the sections for the purpose speci-' fied, said means comprisinga lever pivoted to the last named section intermediate its ends, andlinks connecting the lever at one end with the first named section.

2. In a form lifter, the combination with the form and a supporting pipefor the form, of a lifter comprising a section adapted to be connectedwith the form and having means for engaging the pipe and controlled torelease position by the lifting'of the form with respect to thesupporting pipe, and a section supported by the first named section andhaving means for engaging the pipe controlled to release position by thelifting of the said section with respect to the supporting pipe, andmeans in connection with the last named section and with the supportingmeans for lengthening and shortening the connection between the sectionsfor the purpose specified, the engaging means for the sectionscomprising oppositely ar rangedgripping jaws, a link connecting each jawto the opposite side of the section, said links crossing, and a springpressing the jaws away from the section, said jaws having downwardlyfacing teeth.

3. In a form lifter, the combination with the form and a supporting pipefor the form, of a lifter comprising a section adapted to be connectedwith the form and having means for engaging the pipe and controlled torelease position by the lifting of the form with respect to thesupporting pipe, and a section supported by the first named section andhaving means for engaging the pipe controlled to release position by thelifting of the said section with respect to the supporting pipe, andmeans in connection with the last named section and with the supportingmeans for lengthening and shortening the connection between the sectionsfor the purpose specified, the engaging mechanism for each sectioncomprising a pair of gripping jaws arranged above the sectionforengaging opposite sides of the pipe, connections between the jaws andthe sections for moving said jaws toward the pipe when the sections movedownward with respect to the jaws, and a spring normally pressing thejaws away from the sections.

4;. In a form lifter, the combination with the form and asupportingpipefor the form, of a lifter comprising a section adapted to beconnected with the form and having means for engaging the pipe andcontrolled to release position by the lifting of the form with respectto the supporting pipe, and a section supported by the first namedsection and having means for engaging the pipe controlled toreleaseposition by the lifting of the said section with respect to thesupporting pipe, and means in connection with the last named section andwith the supportlng means for lengthening and shortening the connectionbetween the sections for the purpose specified, the engaging means for ll r l l each section comprising a pair of jaws for engaging the pipe andconnected to the section in such manner that the jaws are re leased andengaged by movement toward and from the sections, and means actingnormally to move the jaws away from the sections.

5. In a form lifter, the combination with the form and a supporting pipefor the form, of a lifter comprising a section adapted to be connectedwith the form and having means for engaging the pipe and controlled torelease position by the lifting of the form with respect to thesupporting pipe, and a section supported by the first named section andhaving means for engaging the pipe controlled to release position by thelifting of the said section with respect to the supporting pipe, andmeans in connection with the last named section and with the supportingmeans for lengthening and shortening the connection between the sectionsfor the purpose specified, the engaging means for each sectioncomprising a pair of opposed jaws for engaging the pipe and connected tothe section by oppositely extending and crossed levers, whereby the jawsare released and engaged by movement toward and from the sections.

6. A form lifter comprising a pair of sections, one of said sectionshaving means for connection with a form, the other section having meansfor moving said other section toward and from the first named section,and a pair of opposed gripping jaws movably mounted on obliquely crossedlevers in connection with each section controlled to release andengaging positions by movement toward and from the adjacent section.

LINUS M. CONVERT.

